OP0019 PREMATURE AGING IN LYMPH NODE STROMAL CELLS OF PATIENTS WITH RHEUMATOID ARTHRITIS PARTY RESTORED BY DASATINIB TREATMENT
Authors: T. De Jong, J. F. Semmelink, J. W. Bolt, C. Grasso, R. A. Hoebe, P. Krawczyk, L. Van Baarsen
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Cellular senescence is a state of proliferation arrest of cells occurring and cleared during normal aging. However, the persistence and accumulation of senescent cells has been implicated in the pathogenesis of age-related diseases like rheumatoid arthritis (RA). Aging is an important risk factor of RA, a chronic autoimmune disease in which loss of immune tolerance and systemic autoimmunity precedes clinical onset of disease. Lymph node stromal cells (LNSCs) are important regulators of peripheral tolerance. Accordingly, accumulating senescent LNSCs may potentially lead to defective peripheral tolerance and the development of systemic autoimmune disease. <h3>Objectives</h3> In this study we investigated the senescence phenotype of LNSCs during health, systemic autoimmunity and RA. Additionally, we examined whether dasatinib treatment could restore their cellular phenotype and function. <h3>Methods</h3> LNSCs were isolated and cultured from inguinal lymph node needle biopsies from autoantibody positive individuals with arthralgia and therefore at risk of developing RA (RA-risk individuals), RA patients and seronegative healthy volunteers. The senescent phenotype and the effect of dasatinib treatment were assessed using quantitative PCR, flow cytometry, microscopy and live-cell analysis. <h3>Results</h3> Cell size, granularity and autofluorescence were significantly higher in RA LNSCs compared with control LNSCs. Stainings indicate more senescence associated β-galactosidase activity, more lipofuscin granules and increased DNA damage in RA-risk and RA LNSCs compared with control LNSCs. Moreover, we found altered gene expression levels of senescence associated genes in LNSCs from RA patients. Functional experiments showed no difference in proliferation and migration capacity between donor groups. Strikingly, the capacity to repair irradiation induced DNA damage was significantly lower in RA-risk and RA LNSCs compared with control LNSCs. Treating LNSCs with dasatinib significantly improved cell size and DNA repair capacity of cultured LNSCs. <h3>Conclusion</h3> We observed premature aging of lymphoid stroma in RA patients and to lesser extent already in individuals at risk of developing RA, which could partly be restored by dasatinib treatment. Premature aging of LNSCs may negatively impact the local niche by inducing inflammation and senescence in nearby cells. However, consequences of prematurely aged lymphoid stroma remain inconclusive providing a rationale for investigating the effect on immune cell responses. <h3>Acknowledgements</h3> We thank our study subjects for participating in the study, the AMC radiology department for lymph node tissue sampling and the rheumatology lab for sample processing. The research leading to these results was funded by an AMC fellowship (to L.G.M.v.B.), the Dutch Arthritis Foundation LLP-30 and the Dutch Organization for Health Research and Development (ZonMw) VIDI n° 91718371 (to L.G.M.v.B). <h3>Disclosure of Interests</h3> None Declared.